Motion pictures as used herein includes all forms of image illustration on two-dimensional surfaces where the images appear to be in motion. Television and movies are two forms of motion pictures. (But not necessarily the only forms.) A two-dimensional surface here means a surface that displays an image in two-dimensional form. Thus, the "surface" itself may be curved or flat.
The concept of generating a perception of depth for images portrayed on a two-dimensional surface (having height and width only relative to the viewer) has existed for many years. Artists of course learned early on that a perception of depth can be achieved by varying size relationships, by strategic shading of objects, and even by changes in crispness of the images.
The concept of generating perceived depth dimension was carried to a new level following the advent of motion pictures. It was appreciated that much of what a viewer sees as depth is due to slight differences seen by the two eyes of a viewer. That is the two eyes being spaced apart see the image from different angles. The differences vary depending on a number of factors and the mind "learns" to recognize these differences as indicating depth. This "new" concept of generating depth relies on artificially imitating certain of these differences. Basically this was achieved by overlaying two near identical but different images on a surface, (e.g., taken by two motion picture cameras spaced apart a distance equal to the spacing of a viewer's eyes and projecting the images simultaneously onto a screen). The projections were also differentiated, e.g., by color or polarization and the viewer was required to view the projected images through special lenses that filtered out one of the projected images to one eye, and the other of the projected images to the other eye. The viewer's mind "sees" but one image and interprets the differences as depth and thus "sees" the third dimension even though it does not exist.
The above concept of three-dimensional viewing was introduced into the motion picture industry some 40 or more years ago. (See introduction to 3-D, Three-Dimensional Photography In Motion Pictures, by H. Dewhurst, the Macmillon Company, New York, 1954, incorporated herein by reference.)
The manner in which a "filmed" motion picture is produced provided yet a further alternative. The typical film projection is a series of still pictures sequentially taken of a moving object. The pictures being rapidly displayed on a screen, the viewer's mind perceives the different positions of objects in the pictures to be movement. Rather than employ two separate projectors, a somewhat three-dimensional effect is achieved by simply alternating the pictures within the sequence. Two similar but different motion picture films are produced and the frames of the two films are interspersed. One of the lenses of the glasses worn by a viewer is darkened and the other is clear. As best understood, the viewer's mind more slowly reacts to the darkened images and the film speed is timed so that the darkened images only are seen by that one eye.
In every case heretofore known, there are two essentials for providing the artificial three-dimensional effect (other than the artist's techniques of shading, etc.). There must be dual images filmed and projected onto the screen and there must be different right and left lenses covering the viewer's eyes that discriminately filter out one or the other of the images projected. Thus, unless the subject is filmed and projected using one of the methods of dual projection of an image onto a common screen to provide discriminate images for viewing by the viewer's right and left eyes, 3-D glasses have not heretofore provided the three-dimensional effect that is desired. There must be different right and left lenses that discriminately filter out the images, and there must be dual images projected onto the screen that are discriminately viewed by the right and left eyes of the viewer.
The present invention is directed to a concept that provides the desired perceived depth dimension using specialized 3-D glasses but which can provide the perceived depth dimension using standard filming, i.e., a single moving picture projected onto a two-dimensional screen.